Wiring a DOL for a compressor

[Van_Denton]

Hi Guys,

Wondering if you can help, I need to wire a DOL for my compressor, it came with this clarke jobby. Ive serached the net but cannot find a wiring diagram (nothing on the clarke site either). Theres lots of diagrams out there but none seem to be the same as this.

Im assuming the earth will go the contact strip on the left but not sure about the rest. Anyone done one of these before?

Thanks
Paul

 

[rtbcomp]

Earth as you say. L1 live from mains, L2 neutral from mains, T1 live to motor, T2 neutral to motor

 

[Van_Denton]

cheers mate, thanks and Wow that was fast!

 

[Spark plug]

Whenever I've wired those motor protection units I've only wired the live through the unit.

Supply in L1, link from T1 -L2, link from T2 - L3 and the load from T3.

 

[brightspark]

Earth as you say. L1 live from mains, L2 neutral from mains, T1 live to motor, T2 neutral to motor

correct
no.link required on single phase

 

[rtbcomp]

I've got that identical unit and it works fine as i described in post #2

 

[brightspark]

the idea of them is is protection for motor overload in places where if there's a power cut they do not trip out and have to be manually reset . ive just fitted one on a waterpump out in a pond in middle of a field

 

[eil]

I would wire it like pdg says or else the overload isn't balanced, It wont trip at the set amperage.

 

[brightspark]

I would wire it like pdg says or else the overload isn't balanced, It wont trip at the set amperage.

come to think of it
the one I did was linked I think short memory

 

[rtbcomp]

I would wire it like pdg says or else the overload isn't balanced, It wont trip at the set amperage.

The overload trips on mine OK

I've removed some of the confusing posts to avoid confusion.

 

[rtbcomp]

Surely in a 3-phase situation you want any one phase to trip the overload in case one phase fails? If any one "channel" being overloaded trips the device then there's no need for the links?

 

[eil]

The overload trips on mine OK

I've removed some of the confusing posts to avoid confusion.

But does it trip at the right amperage ? have you put your clamp meter on to see. With a three pole overload all three poles must have current running through them to balance the overload. There are normally three little bi-metallic thingamy bobs for each pole when you connect only two, the third wont heat up.

 

[rtbcomp]

...There are normally three little bi-metallic thingamy bobs (one) for each pole when you connect only two, the third wont heat up.

True, but if it's mechanically arranged so that any one of strips trips the cutout then there's no need for a balanced overload.

I set the trip by trial & error

 

[eil]

Niked off Google

 

[Spark plug]

Niked off Google

That's a DOL starter with overload protection and no volt release total different ball game to what the op is useing.

 

[rtbcomp]

The one in the OP closes and latches the contacts mechanically by pressing the ON button, the OFF button mechanically releases the contacts.

 

[eil]

The diagram was for the benefit of RTB. So if the OP`s is a totally different ball game does he wire it differently then, I mean not use all the three poles.

Overload built in the OP`s

 

[brightspark]

here http://www.superlecdirect.com/p-ns8...ter-20-25amp?gclid=CPjhiPmRl88CFXQW0wodZqgARg

 

[Van_Denton]

 

[Van_Denton]

well I wired it like was first suggested, I guess I will test it by turning the dial to say 10 amps as the draw from the motor is 14.4 to see if it works?